applettest6_multi_noflash.java

应用java Applet实现的月亮船动画。大家可以看看。

/*本例是用多线程来画动画--航行中的小船*/ 
/*本例用双缓冲来消除闪烁*/ 

import java.applet.*; 
import java.awt.*; 
public class AppletTest6_multi_noflash extends Applet implements Runnable 
{ 
Image bufferImage; 
Graphics bufferGraphics; 
Thread r; //定义一个新的线程，在这个线程的run()中来绘图。 
int xpos; 
int up_down,i; //船上下颠簸值 

public void start() 
{ 
xpos=0; 
i=0; 
up_down=0; 
if(r==null) 
{ 
r=new Thread(this); 
r.start(); //执行线程的start()方法时即调用run() 
} 
} 

public void run() 
{ 
while(true) //这里使用死循环让此线程一直运行，除非你人为中断（如调用此线程的stop()方法） 
{ 
repaint(); 
try { 
Thread.sleep(300); //此线程休眠，其它线程就可以工作（本例中即调用Applet的paint()方法） 
} 
catch(InterruptedException e) {} 
} 
} 

public void stop() 
{ 
if(r!=null) 
{ 
r.stop(); 
r=null; 
} 
} 

public void paint(Graphics g) 
{ 
setBackground(Color.black); 
int w=getSize().width; 
int h=getSize().height; 
int[] wave_len={w/3,w/4,w/6,w/10}; 

xpos+=10; 
if(xpos>=w) xpos=0; 

switch (i) 
{ 
case 0: {up_down=h/40;break;} 
case 1: {up_down=0;break;} 
case 2: {up_down=-h/30;break;} 
case 3: {up_down=0;break;} 
} 
i++; 
if(i==4) i=0; 

bufferImage=createImage(w,h);//以Applet窗口大小来创建bufferImage 
bufferGraphics=bufferImage.getGraphics(); 
/* Image =“画布”，Graphics = “画笔”，Image.getGraphics()方法就是绑定画布和画笔 */ 

bufferGraphics.setColor(Color.green); 
bufferGraphics.drawLine(0, 7*h/10, w, 7*h/10);//画水面 
for(int i=0;i<wave_len.length;i++) //画波浪 
{ 
bufferGraphics.drawLine(w/2-wave_len[i]/2-xpos, 7*h/10+(i+1)*h/40, w/2+wave_len[i]/2-xpos, 7*h/10+(i+1)*h/40); 
bufferGraphics.drawLine(w/2-wave_len[i]/2-xpos+w/2, 7*h/10+(i+1)*h/40, w/2+wave_len[i]/2-xpos+w/2, 7*h/10+(i+1)*h/40); 
bufferGraphics.drawLine(w/2-wave_len[i]/2-xpos+w, 7*h/10+(i+1)*h/40, w/2+wave_len[i]/2-xpos+w, 7*h/10+(i+1)*h/40); 
} 
bufferGraphics.setColor(Color.blue); 
bufferGraphics.fillArc(w/4, h/2+up_down, w/2, h/4, 0, -180); //船仓 
bufferGraphics.setColor(Color.pink); 
bufferGraphics.fillRect(w/4, 5*h/8-h/100+up_down, w/2, h/100); //船弦，高度=h/100 
bufferGraphics.setColor(Color.yellow); 
bufferGraphics.fillArc(w/2-w/12-3*h/16, h/4+up_down, 3*h/8, 3*h/8-h/20, 90, -180); //船帆 
bufferGraphics.setColor(Color.red); 
bufferGraphics.fillRect(w/2-w/12-w/100, h/4+up_down, w/100, 3*h/8-h/100); //桅杆 

bufferGraphics.setColor(Color.white); 
bufferGraphics.fillArc(10, 10, h/4, 3*h/16, 90, -180); 
bufferGraphics.setColor(Color.black); 
bufferGraphics.fillArc(10+h/20, 10, h/4-h/10, 3*h/16, 90, -180); //月亮 

g.drawImage(bufferImage,0,0,this); 
} 

public void update(Graphics g) //覆盖update以使它不在两次画操作之间清屏 
{ 
paint(g); 
} 
}